INTRODUCTION:

The major pests of sugarcane includes the moth borers, termites, white grubs, scales, black bugs, pyrilla, white flies, mealy bug, army worm, grasshoppers, etc., The severe outbreak of woolly aphid Ceratovacuna lanigera (Zehntner) in cultivated regions add it as major pest with great loss in cane yield (7 to 39%) and sugar recovery (1.2 to 3.43%) during last few years (1). There are about 250 aphid species attacking crops (2) in which major species are monophagous and few polyphagous. Recently the woolly aphid C.lanigera, belonging to the family Aphididae, suborder Homoptera and order Hemiptera, has become a serious threat in sugarcane farming.

Biological control methods are now receiving more attention, since these methods, compared to chemical methods are energy saving, non-polluting, ecologically sound, more practicable in sugarcane ecosystem and sustainable. Moreover, as Singh (3) pointed out that increase in resistant pests to pesticides, biological control gains positive value than the chemical pesticides as best available option. Therefore, the present day need is to develop and advocate the bio-intensive integrated pest management methods rather than use of chemical pesticides alone.

The sugarcane ecosystem is such that no methods of pest suppression would be more feasible than the biological control. The natural parasitoids of SWA have been reported by several workers (4, 5 and 6). There are about seven parasitoids, 30 predators and four pathogens affecting woolly aphid. Among them, Dipha aphidivora Meyrick is also a considered as one of the potential predators. It is commonly known as pyralid webber belongs to the family Pyralidae of the order Lepidoptera.

MATERIALS AND METHODS:

The plastic box of size 9cm x 6cm x 3.5cm was used to conduct field biology. This plastic box inverted fixed to the wooden stick by using iron wire. The stick with cage was inserted firmly into the soil near the sugarcane plant. The sugarcane leaf was drawn through the slit made in box along the lateral side. The slit was covered with cellophane tape in order to avoid inward and outward movement of D. aphidivora as predator.

The present work was carried out in Animal science Laboratory of ZA Islamia PG College, Siwan (Bihar) and agricultural fields nearby College campus for field study during two years. The natural condition in the cage ventilation was maintained on upper surface by making minute holes and on lower surface of the cage by covering with copper mesh. The cages were kept in field at suitable place for recording the observations. The fresh young ones were detected from the colony with the help of hand lens and collected with the help of camel hairbrush and released on sugarcane leaf in the cage. Such ten cages were maintained in the field for biological study. Two freshly laid nymphs were released in each cage. The same method was used to study the different instars of D. aphidivora collected from selected two sites of Gopalganj district. The time and date of nymphs release were recorded.

The nymphs were examined to record the time to complete instars once in each twelve hours. The cage can be opened from the lower side and observations were recorded. The summation to total nymphal period and adult period is the total life cycle. The individual predator was maintained in separate cage to know the viviparous potentiality from fourth instar period. The adults were examined to record nymphs laid by adult aphid at an interval of 12 hours. The fecundity was observed until death of adult predators. The biology was carried out in different months under field condition with above procedure implementation. The mean value and standard deviation were calculated for all the biological stages.

RESULTS AND OBSERVATIONS:

The larval period of D. aphidivora limited 22.50 to 28.30 days in the different sugarcane types at selected sites during study period. The larva fed on aphids in CO 238 have shortest (22.50 days) larval period followed by 23.40 days on aphids in COP 79158, moderate on aphids in COP 112 as 25.20 days, whereas maximum duration were observed as 26 days in aphids on BO 138 and 27.30 days in aphids on COC 671 (Figure 1).

Figure 1. Predator biology on SWA in selcted genotypes at Dahibhatta site.

The observation about larval period in sugarcane types at Yadopur revealed minimum 23.52 days on CO 238 followed by 23.45 days on COP 79158, moderate period as 26.25 days on COP 112, whereas maximum 27.15 days on BO 138 and 28.42 days on COC 671 sugarcane genotypes (Figure 2).

The pupal period of the predator at Dahibhatta revealed shortest 4.40 and 4.15 days on BO 138 and COC 671, moderate 4.60 days on COP 112, whereas maximum 7.30 and 7.50 days in aphids on CO 238 and COP 79158 during two years of study period (Figure 1).

This developmental pupa stage showed variation at Yadopur site as shortest 5.40 and 5.65 days on BO 138 and COC 671, moderate 5.60 days in aphids on COP 112, whereas maximum 8.30 and 8.50 days in aphids on CO 238 and COP 79158 during study period (Figure 2).

Similarly, predator has also varied adult longevity in aphids on different genotypes at selected sites for study. The adult longevity of Dipha aphidivora showed minimum 2.40 and 3.10 days in aphids on BO 138 and COC 671, moderate 3.60 days in aphids on COP 112, whereas 4.25 and 4.45 days in aphids on CO 238 and COP 79158 during study period at Dahibhatta site (Figure 1).

The adult longevity at Yadopur site showed minimum 2.40 and 3.10 days in aphids on BO 138 and COC 671, moderate 3.60 days in aphids on COP 112, whereas 4.25 and 4.45 days in aphids on CO 238 and COP 79158 during study period (Figure 2).

Figure 2. Predator D. aphidivora biology on SWA at Yadopur site.

The study on incubation period on aphid fed predator at selected sites showed minimum duration in resistant and maximum on susceptible varieties on both selected sites during study period (Figure 1 and Figure 2). It limited as 3.42 to 7.40 days at Dahibhatta and 4.40 to 8.45 at Yadopur site during investigation period.

The predator fecundity with sugarcane aphid as feed was variable on different sugarcane genotypes at selected sites of study. The fecundity limited to 62 and 56 days as aphid fed predator on BO 138 and COC 671, moderate value 86 days for COP 112, while maximum 94 and 106 days on COP 79158 and CO 238 respectively at Dahibhatta site of study. The fecundity value limited to 72 and 66 days as aphid fed predator on BO 138 and COC 671, moderate value 96 days for COP 112, while maximum 104 and 116 days on COP 79158 and CO 238 respectively at Yadopur site of study in the first generation ranged from 112.00 to 165.00 eggs / female.

The feeding potential of the predator ranged from 828 to 950 aphids at Dahibhatta site during study. The feeding activity were highest in resistant varieties BO 138 and COC 671 as 930 and 950, moderate for COP 112, whereas lowest in susceptible varieties CO 238 and COP 79158 as 828 and 862 days respectively at Dahibhatta site during study. The maximum feeding potential was observed for instar IV followed by instar V, moderate for instar III followed by instar II, whereas very short duration for instar I during investigation at this site (Table 1).

Table 1. Feeding potential of D. aphidivora for aphid on sugarcane varieties at Dahibhatta

Genotype	Instar I Mean	Instar II Mean	Instar III Mean	Instar IV Mean	Instar V Mean	Feeding on SWA
CO 0238	3.29	91.39	198.70	287.34	215.84	828
COP79158	3.68	95.38	208.48	298.06	228.21	862
COP112	3.73	108.62	213.24	301.25	224.37	879
BO138	4.27	101.20	246.03	306.35	242.42	930
COC671	4.31	103.70	252.02	312.60	248.04	950

Table 2. Feeding potential of D. aphidivora for aphid on sugarcane varieties at Yadopur

Genotype	Instar I Mean	Instar II Mean	Instar III Mean	Instar IV Mean	Instar V Mean	Feeding on SWA
CO 0238	4.29	93.39	200.70	289.31	217.82	827
COP79158	4.68	97.38	210.48	300.12	230.24	871
COP112	4.73	110.62	215.24	303.21	226.33	888
BO138	5.27	103.20	248.03	308.33	244.45	939
COC671	5.31	105.70	254.02	314.50	250.12	949

The feeding activity were again highest in resistant varieties BO 138 and COC 671 as 939 and 949, moderate 888 for COP 112, whereas lowest in susceptible varieties CO 238 and COP 79158 as 827 and 871 days respectively at Yadopur site during study. The maximum feeding potential was observed for instar IV followed by instar V, moderate for instar III followed by instar II, whereas very short duration for instar I during investigation at this site (Table 2).

DISCUSSIONS:

The total larval duration was significantly lowest in highly resistant genotype CO 238 followed by COP 79158 (24.38 days) than rest of the studied genotypes. This differential activity is due to some growth promoting substance passed from second trophic level to third trophic level. The aphid consumption in the larval period was significantly low in resistant genotypes than rest of the varieties.

There is lack of literature to discuss the trophic interaction of SWA with D. aphidivora. However, various studies have been carried out about the biology of feeding potential. Tripathi (4) reported 20 -26 days, while Puttannavar (7) observed an average 24.61 days total larval period with 6074.84 aphids feeding throughout the larval period. There is great controversy in regard of larval feeding of D. aphidivora as 4000 aphid (8) and 5868.42 aphids (9) in its life period.

The feeding potential of D. aphidivora which showed the average consumption of 1492.65 aphids in the present study are in variation with the findings of Patil (10) and Mulimani et al. (11). However, the total feeding potential of D. aphidivora 1372.65 aphids were observed in the present study is slightly higher than the observations (1000 aphids) of Mulimani et al., (11). This may be due to favorable climatic factors that prevailed in the study area.

CONCLUSION:

The study clearly indicated predator potential to check sugarcane population in two selected sites of Gopalganj district. It relies that predator efficiency is more common in irrigated site rather than floodplain sites. This study is useful in perspective natural control of sugarcane aphids without increase in pollution level through pesticide drainage in case of chemical control with different pesticide concentrations.

REFERENCES:

1. Patil RK, Ramegowda GK, Rachappa V, Lingappa S and Tippannavar PS (2003): Record of woolly aphid, Ceratovacuna lanigera Zehntner (Homoptera: Pemphigidae) on sugarcane in Northern Karnataka. Insect Environment, 9: 57-58.

2. Blackman RL and Eastop VF (1984): Aphids on the World’s Crops, An identification Guide, John Wiley and Sons, New York, 466.

3. Singh SP (1999): Biological control in India. Indian Journal of Plant Protection, 126-138.

4. Tripathi GM (1995): Record of parasite and predator complex of sugarcane woolly aphid, Ceratovacuna lanigera Zehntner in Nagaland, Indian Sugar, 44: 883-885.

5. Puttannawar (2004): Bioecology and management of sugarcane woolly aphid, Ceratovacuna lanigera, Zehtner (Homoptera: Aphididac) MSC (Agri.) Thesis, Univ. Agric. Sci., Dharwad (India).

6. Anonymous (2002): Sugarcane pests and their control. In: The Philippines Recommendations for Sugarcane. Sugarcane Research Foundation, Philippines, 139-186.

7. Rabindra RJ, Mohanraj P, Poorani J, Jalali SK, Joshi SS and Ramani S (2002): Ceratovacuna lanigera Zehntner (Homoptera: Aphididae), a serious pest of sugarcane in Maharashtra and attempts at its management by biological means. Indian Journal of Applied Entomology, 16: 171-172.

8. Patil AS and Nerker YS (2004): Status report of sugarcane woolly aphid Ceratovacuna lanigera, Zehntner, a new pest of sugarcane in Maharashtra State, Vasantadada Sugar Institute, Pune, Maharashtra.

9. Kulkarni KA and Mallapur CP (2005): Development of biocontrol strategies for the management of sugarcane woolly aphid, Ceratovacuna lanigera Zehntner (Homoptera: Aphididae). The DBT Project Progress Report Submitted Principal Investigator and Project Director, Project Directorate of biological control (PDBC) Bangalore, 2005.

10. Patil AS (2003): White Woolly Sugarcane Aphid, Ceratovacuna lanigera: A New Pest of Sugarcane in Maharashtra, Proceedings of State-Level Seminar on Pest Management for Sustainable Agriculture, Feb. 6-7, 2003 at MAU Parabhani, pp. 33-37.

11. Mulimani V, Patil RK, Lingappa S and Malthesh SP (2004): Sugarcane woolly aphid, Ceratovacuna lanigera Zehntner and its predators. Insect Environment, 10: 116-117.

Received on 17.05.2023 Modified on 12.06.2023

Research J. Science and Tech. 2023; 15(3):165-168.

DOI: 10.52711/2349-2988.2023.00027