Berothidae

Wedmann, Sonja, Makarkin, Vladimir N., Weiterschan, Thomas & Hörnschemeyer, Thomas, 2013, First fossil larvae of Berothidae (Neuroptera) from Baltic amber, with notes on the biology and termitophily of the family, Zootaxa 3716 (2), pp. 236-258 : 243-245

Berothidae indet., larva C

Figs. 6 , 7

Chrysopidae : Janzen 2002: Fig. 58.

Material examined. Specimen No. 1270- 1 in the private collection of Christel and Hans Werner Hoffeins (Hamburg, Germany); a third instar larva in a piece of Baltic amber (precise collecting locality is unknown), which itself is embedded in a block of artificial resin.

Description. Larva about 5.5 mm long (including mouthparts), preserved slightly curved at its anterior and posterior end.

Head capsule 0.47 mm long, 0.2 mm wide (length/width ratio 1.6). Stemmata not visible, but ocular area apparently present; two long setae (S4, S9) in this area clearly visible. Dorsally, ecdysial cleavage lines poorly preserved; consisting of frontal and coronal sutures. Two arms of frontal suture extending for approximately two thirds of head capsule length, convergent from inner margin of antennal tubercles until they touch; lateral sutures absent; coronal suture short. Ventral view of head mostly obscured.

Mandibles and maxillary blades forming mandibulomaxillary stilets, about 0.4 mm long; broad basally, gradually narrowing and pointed apically (but not very acute).

Antennal sockets located on distinct projections (antennal tubercles). Right antenna seven-segmented, 0.42 mm long; left antenna six-segmented, 0.43 mm long. Basal segments elongate and strongly conical, basally less than 0.01 mm wide, and distally about 0.02 mm wide. The other antennal segments rectangular, about 0.02 mm wide. Length of segments from base to top: 0.06 mm, 0.1 mm, 0.05 mm, 0.05 mm, 0.09 mm, 0.08 mm (left antenna); 0.06 mm, 0.08 mm, 0.03 mm, 0.03, 0.05 mm, 0.09 mm, 0.08 mm (right antenna). No annulation visible on surface of antennal segments.

Right labial palpus visible in ventral view ( Fig. 7 C), consisting of at least 6 segments (additional, basal-most segment might be present). All segments (except for apical one) about 0.02 mm wide; apical segment about 0.01 mm wide (basally). Length of segments of right labial palpus from base to top: 0.05 mm, 0.09 mm, 0.03 mm, 0.08, mm, 0.08 mm; apical segment pointed apically, 0.05 mm long. No annulation visible on surface of palpomeres.

Cervix probably strongly retracted into prothorax; in dorsal view visible only as lateral scale-like structure. Prothorax 0.52 mm long, 0.52 maximum width; with two large dorsal sclerites located anteriorly and in contact with each other along midline. Mesothorax and metathorax both approximately 0.4 mm long and 0.6 mm wide, both with pair of small oval dorsal sclerites.

Legs short, robust; coxa very short; trochanter distinct, short; femur, tibia and tarsus relatively short, stout; pretarsus with two short claws, trumpet-shaped empodium.

Abdomen divided into 10 segments, terminal segments poorly visible. Segments 1 to 4 much shorter than wide, about 0.3–0.4 mm long and about 0.6–0.7 mm wide. Segments 5 to 7 about 0.5 mm long, and 0.7 mm wide. Segment 8 (and following two) gradually tapering towards end of abdomen (due to clouded preservation not measurable). Apex of abdomen obscured by cloudy, rounded vesicle, perhaps consisting of fluid leaking into resin.

Remarks. Judged from its size, this larva is a third instar (the second instar larvae of Berothidae are inactive and exhibit morphologically reduced legs and mouthparts).

This larva was schematically figured earlier (Janzen 2002: Fig. 58); the author erroneously assigned it to the family Chrysopidae .

Figures

FIGURE 6. Berothidae indet., larva C. Photograph of the larva, dorsal view. Scale bar is 0.5 mm.

FIGURE 7. Berothidae indet., larva C. A, photograph of the head, dorsal view. B, drawing of the head and thorax, dorsal view. C, labial palpus. D, right foreleg, ventral view. an, antenna; cs, coronal suture; cx, coxa; ds, prothoracic dorsal (pronotal) sclerites; em, empodium; fm, femur; fs, frontal suture; tb, tibia; tr, trochanter; ts, tarsus. Scale bars are 0.5 mm (B – D to scale).