Mesomantispinae Makarkin 1996

Mesomantispinae

Mesomantispinae is composed of six genera and nine described species, and two indeterminate species one of Archaeodrepanicus (Jepson et al., 2013) and one Mesomantispinae gen et sp. indet. (herein), the species are listed in Table 1, other undescribed Mesozoic Chinese Mesomantispinae fossils have also been discovered (Makarkin et al., 2012). The subfamily represents one of the earliest records of the family Mantispidae, first recorded in the Middle–Upper Jurassic of Daohugou, China. The only older known mantispid is from the Lower Jurassic of Germany, Liassochrysa stigmatica. To date mesomantispines have only been found in Asia (China, Kazakhstan, and Siberia). Another mantispid is also known in the Kazakhstan fauna, Promantispa similis Panfilov, 1980, which is thought to be sister group to Liassochrysa ( Wedmann & Makarkin, 2007; Liu et al., 2015), both being placed within the extant subfamily Drepanicinae (Liu et al., 2015). The first record of mantispids in Europe and then their absence until the Eocene, may represent a lack of fossil localities, or specimens not yet discovered, or only sparse distribution or diversification compared to the diverse fauna observed in Asia.

The presence of raptorial forelegs on the mesomantispines suggest a predatory lifestyle, as observed in the extant mantispids. A major difference however is the absence of a large sub-basal spine on the fore femur, which is considered to be a plesiomorphic condition of Mantispidae. The adaptive significance of the large sub-basal spine is unclear, but it cannot be excluded that its presence facilitates capturing of prey, so in this respect members of the extant subfamilies of Mantispidae may have had an advantage over mesomantispines.

Nothing is known about the larvae of mesomantispinae, therefore no interpretations about larval lifestyle can be made, such as whether they had a relationship with spiders, as observed in modern Mantispinae and some extinct taxa (Ohl, 2004).

The genera of Mesomantispinae are mostly differentiated on their body morphology, for example the structure of their raptorial forelegs, which is quite variable, ranging from clubbed, oval, to slender. Variation is also observed with the length of the pronotum, which ranges from relatively short to elongate. The wing venation on the whole is similar between the genera, however, some venation characters can be used to group genera together. Examples of this are the crossveins within the CuP area, separating Mesomantispa from the other genera, and also the structure of CuP, whether it is pectinate (Clavifemora, Sinomesomantispa, Archaeodrepanicus) or non-pectinate (Karataumantispa, Ovalofemora gen. nov., Longicollum gen. nov.).

Below is a key of Mesomantispinae genera, updated from Jepson (2015) to include the newly described genera:

1. Crossveins between branches of CuP present; area posterior to CuA approximately half the width of the wing...................................................................................................... Mesomantispa

- Crossveins between branches of CuP absent; area posterior to CuA less than half the width of the wing................. 2

2. Forewing CuP pectinate, prostrate setae on foretibia not hooked, foretibia and foretarsus combined longer than forefemur... 3

- Forewing CuP non-pectinate, prostrate setae on foretibia hooked, foretibia and foretarsus combined longer than forefemur...................................................................................................... 5

3. Forelegs greatly enlarged to give a club-like appearance (Jepson et al., 2013: fig. 7); forewing colour pattern consists of spots........................................................................................... Clavifemora

- Forelegs not club-like in appearance; no spots on forewings.................................................... 4

4. Wide fore femur (1.7 mm) and very small fore femoral spines (<0.1–0.16 mm long) (Jepson et al., 2013: Fig. 6B); costal margin concave before mid-point of wing; costal space of forewing sharply narrowed towards apex; RP with 9 branches, simple for most of their length; forewing colour pattern consists of a distal distinct thick dark band (Jepson et al., 2013: fig. 6A)......................................................................................... Sinomesomantispa

- Fore femur more slender (0.9–1 mm) and relatively larger femoral spines (0.1–0.25 mm long); costal margin not concave before mid-point of wing; RP with 6 branches, some branches forked before mid-point of wing; forewing colour pattern consists of 3 stripes (Jepson et al., 2013: fig 1A)................................................. Archaeodrepanicus

5. Length to width ratio of forefemur (at widest part) is less than 3, forefemur oval shaped, forecoxa, foretrochanter stout, all covered in setae........................................................................ Ovalofemora gen. nov.

- Length to width ratio of forefemur (at widest part) is 3 or more, some setae........................................ 6

6. Forefemur and forecoxa slender, pronotum slightly elongate 1.1x longer than wide, MP deeply forked..... Karataumantispa

- Forefemur widened at proximal end, with spines at distal apex, pronotum very elongate 2.8x longer than wide, MP simple most of length forking distally.......................................................... Longicollum gen. nov.