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Diaxenes dendrobii
Classification
Diagnostic Features of Larvae
- Mature larva. Form slender, cylindrical. Length up to 21.5 mm; maximum breadth (at prothorax), 3 mm. Head scarcely depressed, slightly wider before middle (maximum head-width, 2 mm), with sides rather strongly converging for posterior half; antennal foramen very narrowly open behind; mouthframe very narrowly sclerotized, with a row of eight setiferous pores; six epistomal setae present. One pair of ocelli present; lens very strongly convex; pigmented spot very distinct. Hypostoma fiat, testaceous, with front margin very narrowly ferruginous; two pairs of paramedian, setiferous pores present; sutures distinct, ferruginous, slightly curved. Gular region undefined. Antenna two-segmented, the second segment slightly elongate and bearing a tapering, hyaline process. Maxilla with third segment bulbous, distinctly shorter than second. Labial palp with third segment bulbous, less than half length of second. Mentum not distinct from submentum. Prothorax with pronotum feebly rugose and with rather long scattered setae near margins. Eusternum well defined, with several long setae. Abdomen with each dorsal ampulla with a single transverse furrow, and two transverse rows of glabrous tubercles, anterior to which are a few irregularly arranged ones. Ventral ampullae with two rows of tubercles. Ninth segment simple. Epipleurum slightly protuberant on all segments. Pleural tubercle with sclerotized pits absent. Anus trilobed. Legs absent. Spiracles with peritreme rather thick, almost round.
Pupa. Length, 10-15.25 mm; maximum breadth, 5.25 mm. Head with vertex partly visible from above, very deeply and broadly excavated between bases of antennae, and bearing two pairs of setae; .front with several very long setae arising from papillate bases; clypeus with six setae near base, but the transverse impression very feeble. Antennae extending as far as second or third abdominal segment, where they are curved downward to terminate near mid coxae. Eyes feebly convex, glabrous. Mandibles each with two long setae (arising from papillate bases) near middle of outer face. Labrum semicircular, bearing about six setae. Pronotum bearing numerous long fine setae arranged more or less in three rows. Mesonotum smooth, with four to six shorter setae on each side of scutellum which is slightly protuberant. Metanotum smooth, and with eight to twelve setae on each side of scutellar groove. Elytra and wings extending as far as fourth or fifth abdominal segment. Abdomen with tergites one to six each with a transverse row of short stout spines near posterior margin. Seventh tergite elongate with sides slightly tapering and bearing a transverse row of much stouter spines near middle, above which are a few smaller ones. Eighth tergite short, transverse, with hind margin slightly rounded, and front margin bearing a row of spines. Ninth segment deeply divided beneath, and bilobed, each lobe bearing several very short conical spines. Sternites four to eight glabrous. Legs with about five long fine setae near apex of each femur; mid and hind femora each with a tapering tuberculate process near base; hind femora extending to fourth abdominal segment; tibiae directed posteriorly. Functional spiracles present on first six abdominal segments, but a vestigial pair present on segment seven; peritreme round to very broadly oval, very thick, and slightly raised above general level of cuticle. Adapted from Duffy (1953).
Biology and Economic Importance
- Members of this tribe are known from various host plant families. Species of this tribe are potentially invasive outside their native range.
Selected References to Larvae Specimens
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