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Mallodon downesii
Classification
Diagnostic Features of Larvae
- Mature larva. Length up to 85 mm; breadth (at prothorax) 18 mm. Form subcylindrical, very robust, slightly tapering posteriorly to segment 9. Head moderately depressed, slightly transverse (maximum head-width 10.6 mm). Genae very strongly shouldered, rugose, pitchy and bearing a few pale setae. Mouth-frame strongly sclerotized rugose, broadly pitchy. Frons with a broad, pitchy anterior margin comprising a heavily sclerotized ridge which is abruptly sloping; upper boundary varying from straight to slightly crenulate, keel-shaped, notched medially and produced beyond lower boundary in two paramedian lobes; lower boundary with a pair of broadly triangular lobes projecting over each side of clypeus. Postcondylar carina distinct. Subfossal process large, acutely conical. Antenna 2-segmented; segment 2 obliquely truncate apically and bearing sensory pores and setae. Three pairs of ocelli present which are sometimes partly obscured by the heavy sclerotization of gena. Mandible very robust, pitchy, shining, with outer face strongly rugose. Labrum oval, leathery, partly ferruginous and coarsely and densely setose anteriorly. Gula extremely short, with sutures diverging to meet anterior portion of occipital foramen. Prothorax moderately depressed, obliquely inclined, about twice as broad as long; pronotum rectangular, delimited laterally by a pair of grooves; median cleavage line shallow; rather indistinct; anterior area rugose and bearing numerous scattered reddish setae; posterior area coarsely and irregularly rugose and sparsely setose. Eusternum incompletely separated from presternum. Presternum with lateral areas each bearing a group of teat-like tubercles (which are strongly sclerotized apically) and a large conical, fleshy protuberance, possibly of a sensory nature. Mesonotum and metanotum smooth, almost glabrous. Abdomen with dorsal and ventral ampullae on segments 1-7; each ampulla with two distinct transverse furrows, faintly rugose, glabrous. Pleural discs present on segments 1-7; indistinct, slightly wrinkled, feebly sclerotized and testaceous. Segments 8 and 9 feebly rugose, the latter large, slightly extended, with scattered fine setae. Anus trilobed, each lobe strongly protuberant and bearing scattered, long, fine setae. Legs rather short, slightly longer than maxillary palpi, ferruginous, setose; unguiculus attenuated. Spiracles of mesothorax broadly oval; metathoracic pair minute; abdominal spiracles with peritreme broadly oval, thick and slightly raised above general level of cuticle. This larva possesses a well-developed proventriculus which is equipped internally with a strong, stout, subquadrate sclerite. First-instar larva. In this instar only, abdominal segments 3 and 4 are each equipped with a pair of egg-bursting spines. Each spine is straight, needle-like and arises from a bulbous basal tubercle.
Pupa. Length (excluding mandibles) up to 51 mm; maximum breadth 16 mm. Head salient, not concealed from above by prothorax; vertex longitudinally strigose, with a deep median, longitudinal impression, on each side of which is a group of setose papillae. Mandibles extending anteriorly, robust, sickle-shaped (in male) and spiculate. Antennae thick, extending as far as abdominal segment 2. Pronotum strongly transverse; sides parallel, slightly crenulate; disc transversely strigose, with a narrow, smooth, longitudinal, median impression and scattered setose papillae. Mesonotum with similar striae and papillae; scutellum prominent, fleshy, papillate. Metanotum transversely striate with papillae mainly grouped in an arc, and with a fleshy subconical tubercle near each anterior angle. Elytra and wings extending as far as abdominal segment 3. Abdomen with tergites rugose and bearing numerous scattered ferruginous spinules; gin-traps present on segments 2-3, 3-4, 4-5, 5-6 and 6-7; each consisting of two transverse subcarinate, labiate protuberances. Sternites with spinules less numerous. Legs with hind femora extending only as far as abdominal segment 3. Functional spiracles present on abdominal segments 1-6, the seventh pair being closed and probably non-functional; peritreme narrowly oval and rather thick.
Egg. Length 3.25 mm; breadth 1.5 mm. Form ovoid, with one end bluntly tapering and the other more strongly tapering and truncate apically. Chorion light brown, covered with dark brown coarse reticulation; micropylar area distinct, pitchy. Adapted from Duffy (1957).
Biology and Economic Importance
- Biology and economic importance for this taxon coming soon.
Selected References to Larvae Specimens
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