Opostegidae  

Diversity description:

Opostegidae adult   Currently 7 genera, 197 species, and 2 subspecies are recognized (including 2 species of Pseudopostega and 7 species of Opostegoides which were described but unnamed by Puplesis and Robinson, 1999.  Of the 197 species currently known, approximately 87% occur in subtropical to tropical regions. Of these, 84 species (or 42% of the world fauna) are known to be restricted to the Neotropical Region. Four of the seven genera now recognized within Opostegidae occur in the New World. Notiopostega consists of a single species from the Valdivian forests of southern Chile. The genus Neopostega is comprised of 6 species endemic to the Neotropical Region. The predominantly Palearctic/Indomalayan genus Opostegoides is represented in the New World by a single, widespread species, O. scioterma, across the northern United States and southern Canada. It is possible that this species may have been an early introduction into North America, although no known Old World species appears conspecific. The highly apomorphic genus Pseudopostega is by far the most diverse genus in both hemispheres with 84 New World species now recognized (92% of the total fauna for this region). The Oceanic genus Paralopostega is comprised of 6 species endemic to the Hawaiian Islands. Eosopostega, originally described from southern Japan, is now known to include a second species from the Moluccas Islands of Indonesia (Puplesis and Robinson, 1999). The distributional limits of the Old World genus Opostega will continue to be uncertain until the remaining unstudied species originally attributed to ‘Opostega’ have been dissected. Currently it is believed that most of these species will be transferred to other genera, most probably Pseudopostega, with the primary center of true Opostega lying within the Palearctic Region.

Geographic Range:

Nearctic, Palearctic, Oriental, Ethiopian, Neotropical, Australian, Oceanic Island

Larval head description:

Head depressed, triangular, with shallow epicranial notch and poorly defined sutures. One pair of stemmata. Mandible with a single, large, minutely spinulose seta. Cranium with a prominent pair of apophyses extending caudad into T1 and 3 pairs (dorsal, lateral, and ventral) of prominent, internal, longitudinal ridges. Development slightly hypermetamorphic with spinneret not fully formed until last (6th) instar.

Secondary setae:

absent

Body setae on verrucae:

absent

Body setae on chalazae:

absent

Body setae on scoli:

absent

Larval body description:

Opostegidae larval morphology Body whitish in color, extremely slender, 8–25 mm long, and apodal, with paired ventral callosities on T2-3.

Spinneret:

present

Thoracic glands:

absent

Thoracic legs:

absent

Larval Prothoracic L-group setae:

trisetose

Abdominal glands:

absent

Abdominal prolegs:

absent

Anal comb on A10:

absent

Reproductive system:

Monotrysian

Oviscapt (ovipositor):

non-piercing

Female genitalia description:

Opostegidae female genitalia   Oviscapt non-piercing, short, barely extending beyond A7. Papillae anales dorsal, usually paired and setigerous but occasionally fused, absent in Opostegoides. Anterior apophyses usually absent; posterior apophyses always present, either short or elongate and variably furcate caudally. Oviporus located terminally due to extreme reduction of A8, 9+10. Ductus bursae usually membranous, often with minute, internal, sclerotized pectinations. Corpus bursae usually a large membranous sac, without a well defined signum but often with inner walls variously covered with minute spicules and/or with an elongate, indistinct band bearing numerous, minute, tubercular outgrowths from wall of bursa (particularly in Pseudopostega).

Female corethrogyne:

absent

Female pregenital sexual scales:

absent

Female accessory glands:

one pair

Female oviduct opening:

below anus

Male coremata:

absent

Male pregenital sexual scales:

absent

Male genitalia description:

Opostegidae male genitalia   Uncus reduced, typically a slender bridge between a pair of widely separated setose lobes (socii), rarely in the form of a medium connate lobe (in Eosopostega). Tegumen reduced to a narrow dorsal ring. Vinculum usually a narrow, rounded ventral ring; anterior margin deeply concave in Opostegoides, Eosopostega, and in a few species of Pseudopostega. Gnathos fused, variable, usually a well developed ventral arch or plate. Transtilla typically absent, rarely present as a slender, median bridge. Juxta highly variable, usually absent, or, if present, varying from a slender, midventral projection arising from the vinculum, to a broad membranous plate, or curved, spiniform rods connecting valvae. Valvae variable in outline, with a distinct costal process (apophysis) extending inward from base but articulated in Pseudopostega and some Neopostega; apex of valva (cucullus) an ovoid, pectinated lobe joined to basal half of valva by a slender to broad pedicel. Sclerotized aedoeagus present in varying degrees in Notiopostega, Neopostega, Opostegoides, Paralopostega, and Eosopostega; phallus entirely membranous in Opostega and Pseudopostega.

Sternum 4:

with fenestra

Sternum 5:

without fenestra

Sternum 5 gland:

absent

Adult abdomen description:

Sternum 2 large, weakly sclerotized, usually with a large, central, partially or completely divided hyaline area.

Male has:

phallotheca and aedeagus (phallus), only phallotheca