Importance of the chaetotaxy in larval identification of Galleria mellonella (Linnaeus) (Lepidoptera: Pyralidae) along with some notes on its life history

Earlier studies on identification of Galleria mellonella emphasized mainly on characterization of wing venation and maculation, larval or pupal morphology and other taxonomic characters such as male and female genitalia. The larval identification and diagnostic characters of pest species can best be strengthen through diagnosis of the setal arrangement and position of punctures present of different larval body segments. The cephalic region and all the bodily segments such as thoracic, abdominal etc of the last instar larva of Greater waxmoth, Galleria mellonella (Linnaeus) belonging to family (Pyralidae) have been examined along with some biological aspects.


Introduction
Galleria mellonella (Linnaeus) belongs to subfamily Galleriinae (family Pyralidae) also known as greater wax moth. Earlier workers such as Fabricius and Walker classified this pest as G. cereana and G. obliquella respectively. The current nomenclature of this pest species was given by Linnaeus, who reclassified it as G. mellonella (Linnaeus). The larvae of G. mellonella Linnaeus make a tunnel into the periphery of unsealed cells of the bee species Apis mellifera Linnaeus and A. cerana Fabricius. Worldwide, a small group of workers such as Mathur (1954 and1959), Mathur and Singh (1963), Azam and Ali (1965), Franzmann and Garrett (1978), Yoshiyasu (1980), Goel and Kumar (1981), Stehr (1987), Lin 1995, Amutha andDavid (1998), Rose and Singh (2010) and Pinheiro et. al., (2011) have attempted chaetotaxic studies of few species. Due to the paucity of proper information on this pest, the chaetotaxic and biological studies were initiated to identify this species at its imago stage.

Material and Methods
The caterpillars of this serious pest collected from the infested beehives and reared in the Lepidoptera laboratory for collecting further information on its life history. For chaetotaxic studies, the last larval instar body was first distended by boiling it in the test tube which then spread on a glass slide by giving a long ventral cut with a surgical blade. For proper maceration, cephalic region and the remaining body were kept in 10% KOH separately followed by wash in 1% glacial acetic acid and then preserved in 70% alcohol and glycerin in the ration of 9:1 for further studies (Stehr, 1987). To study setal arrangement, larval heads shifted to watch glass containing glycerin whereas permanent slides of thorax pore MDa.; MD1 posterolatrad to P2; MD2 posterolatrad to MD1; MD3 posterad to MD1; Pore MDa present much closer to MD2 than MD3.
A10: Anal shield well developed oblong; seta D1 present near anterior margin of the shield; D2 longer in length than D1; D2 lies at distal margin of the shield. SD1 anteroventrad to D2; SD2 present near lateral margin of the shield; SD2 anteroventrad to SD1; SD1 longer than SD2. Lateral group present at lateral margin of the anal leg with seta L1 present interiorly; L3 posterodorsad to L1; L2 anteroventrad to L3. Subventral group composed of setae SV1, SV2, SV3 and SV4; seta SV1 anteroventrad to L3; SV2 posterocaudad to SV3; seta SV1 and SV3 almost in straight line, SV3 ventrad to SV1. V1 seta of ventral group present towards ventral meson and slightly but ventrad to seta SV4.

, 2, 3 and 4)
Being the element of family Pyralidae, Galleria mellonella, is universally known as the greater wax moth. As the name indicates, it infests the honey bee hive by burrowing into the frame of the unsealed cells which causes Galriasis during the course of present studies; the various life history aspects have been studied very precisely to strengthen the information of this pest.
The eggs are dirty white in colour, ovoid and smooth, laid in crevices of bee hive in clusters of 50-100.The first instar larvae thus hatched out of egg shell passes through a total of seven larval instars to become prepupal/mature larva. To control this pest at an appropriate time, all the most concerned and important information like physical dimensions and time taken by the caterpillar up to maturity is given in the tabulate form below.

Adult Description
Frons and vertex ochreous; antennae simple, light brown; forewing with costa straight, apex rounded, outer margin convex, tornus rounded, anal margin almost straight, concave near base, ground colour ochreous; hindwing with ground colour white ochreous, costa straight, apex rounded, outer margin concave, tornus rounded, anal margin straight, cilia white; abdomen pale yellow; legs covered with white scales.