Taxonomic Studies of the Genus Megachile from Coniferous Forests of Khyber Pakhtunkhwa, Pakistan

Very little is known about the Megachilid bee diversity from Pakistan. In this context, a study primarily focused on Genus Megachile Latreille 1802 from grassland and meadows of coniferous forests of Khyber Pakhtunkhwa Province was conducted. Eight species were recorded, two species ( Megachile albifrons , Smith 1853, Megachile pseudodisjuncta, Kumari 2018) are new record to Pakistan, whereas all the eight species are new record to Khyber Pakhtunkhwa Province. Brief description together with illustrations and distributional range of each of these Megachile species is also provided. A diagnostic key for identification of the female species of Genus Megachile Latreille 1802 for Pakistan is provided for ready reference.


INTRODUCTION
M egachilidae being third largest and diverse family of bees, containing more than 4000 described species worldwide (Michener, 2007;Ascher and Pickering, 2020). The Megachilid are long-tongued bees having the scopa (pollen collecting hairs) under the metasoma except parasitic Megachilid bees. Among Megachilid bees the Genus Megachile Latreille 1802, being diverse bee genera, with more than 1525 described valid bee species and with more than 50 subgenera worldwide (Ascher and Pickering, 2020). This genus consists of leafcutter bees, mason bees and resin bees (Sardar et al., 2021). Currently more than 150 species of Genus Megachile in a several subgenera are recognized as valid Southeast Asian species (Ascher and Pickering, 2020). Taxonomic studies on Genus Megachile Latreille, 1802 bear a lot of significance, because of their role as main pollinators in agro-landscape ecosystems. Taxonomic studies provide information on the identification, classification as well as their diversity and also provide floral association which will contribute to the better understanding of pollination biology in relation to important crop plants. So far, the study of bees fauna of Pakistan has been poorly studied, thus the identification of Megachilids from grassland and meadows of coniferous forests of Khyber Pakhtunkhwa is important. The conifer forests in Pakistan play a significant role in the natural ecosystem, because of their role as watershed protection, supplying timber, habitat for biodiversity and non-timber forest produce and also grazing land for domesticated animals (Ahmad et al., 2012;Ahmed et al., 2006). The specific objectives of this research study were to explore the diversity and distribution of Megachilid bees from coniferous forests of Khyber Pakhtunkhwa Province.

MATERIALS AND METHODS
The present study is restricted to the species of the Genus Megachile Latreille, 1802 from coniferous forests of Khyber Pakhtunkhwa Province. While bees were visiting on the flowers, they were collected. Then bees were killed with ethyl acetate. After collection, bees properly stretched and then followed for preservation. Keys known for eminent workers of Oriental region like Bingham (1897), Gupta (1993) and Michener (2007) were followed. The morphological terminology and classification used in the descriptions follows Michener (2007).
Descriptions are provided for all species present in the current list. Megachile specimens were investigated by using a Nikon Stereo Zoom Microscope SMZ 18 (Nikon, Minato City, Tokyo, Japan). Digital images were acquired by employing camera DS-Fi2 (Nikon) attached O n l i n e

F i r s t A r t i c l e
to the stereo zoom microscope; images were refined with Helicon Focus image stacking software and then finely tuned by Adobe Photoshop software.

Diagnosis
Body black and robust, covered with white, yellowishgrey or reddish-brown, short or long pubescence. Head rounded, female mandibles 3-5 teeth seldom with 6 teeth; mandibles with or without cutting edges, cutting edges if present than at the base of one or more interspace; in males mandibles narrower, 2-3 dentate, with a long triangular process ventrally, scutellum without prominent axillary spines. Arolia absent, in female scopa (pollen collecting hairs) present on Sternum S2-S5, sometimes on S6, entirely absent on hind tibia. In males tergum 6 with a narrow ventral tooth laterally or without it.

Diagnostic Key of the Females of the Genus Megachile Latreille, 1802 from Pakistan
(Modified from the key by Bingham, 1897;Michener, 2000)

Description
Body length 14.25-17.82mm; clypeus convex, rounded anteriorily and hidden under thick pubescence, clypeus with median longitudinal impunctate line, mandible 6 dentate with incomplete cutting edge on 2 nd and 3 rd interspace; dense white pubescence on face, thorax covered with white pubescence on lateral sides, forewing is dark fuscous apically and subhyaline basally, anterior leg with fuscous pubescence mixed with few white hairs, intermediate and posterior legs with few white hairs, tarsi fuscous on posterior side, scutellum coarsely and finely punctured, abdomen slightly metallic, on both sides of the basal abdominal segments a square patch of white pubescence, apical margins of the segments T2-T3 with a transverse fasciae, complete fasciae present on T3-T5; tegulae black in colour; T6 disc clothed with black hairs; scopa S2-S5 with white hairs, S6 with erect black hairs.

Material examined
Pakistan

O n l i n e F i r s t A r t i c l e Distribution
Oriental region (Veereshkumar, 2015). New record to Pakistan.

Distribution
Oriental region, Palearctic region and Afrotropical regions (Gonzalez et al., 2019;Genaro, 1996;Moure et al., 2007;Raw, 2007;Meurgey, 2016;Ascher and Pickering 2020). New record to Pakistan.  (Cockerell, 1918 Description Body length 4.5-6.1mm; body black, head and thorax finely punctured, white pubescence on face, clypeus slightly convex with a median longitudinal line, clypeus anterior margin slightly arched, mandibles quaridentate with very small cutting edge in second interspace and complete cutting edges in third interspace; abdomen cordate; wings hyaline with fuscescent along the apical margin; fascia of abdominal segments yellowish white; scopa pale white from S2-S5 except S6 where it is black in colour; mid and hind trochanter and femora entirely dull orange, posterior tibia and tarsi with pale whitish hair; white transverse bands on apical margins of abdominal segments T1-T5.

Material examined
Khyber

Megachile (Callomegachile) pseudodisjuncta (Kumari, 2018)
Female (Fig. 5) Description Body length 13.15-14.83 mm; clypeus convex, arched anteriorily, mandible tridentate without cutting edges, mandible with prominent carina at the base, face with black pubescence, lateral aspect of thorax with mixture of black and white hairs, scutum slightly convex, bare, scutellum with carinate on lateral side, swollen pronotal lobe, tegula black, wings hyaline. T1 with mixtures of white and fulvous hairs, T2-T6 long erect black hairs on lateral aspect, scopa bright fulvous from S2-S5, S6 with black hairs, mid and hind tibia with white hairs on posterior side, red hairs on anterior side of tarsal segments.

Distribution
Oriental region (Kumari and Kumar, 2018). New record to Pakistan.

Description
Head wider than the thorax, head and thorax strongly punctuate, clypeus slightly emarginate, mandible with 5 teeth, incomplete or rudimentary cutting edge in the 2 nd interspace and conceal cutting edges in the 3 rd interspace, supraclypal region with carinate, Head, thorax and anterior metasoma clothed with orange hairs, white hair bands on lateral aspect of abdominal segments T2 to T4, but fulvous on T1, forewing red at base, fulvo-hyaline at apical side, posterior tarsi fringed with long white pubescence, first four abdominal segments have entire fulvous hair-bands, scopa pale white from S2-S5, black on S6.

Distribution
Oriental region (Pauly and Munzinger, 2003;Ascher et al., 2016) (New record to Pakistan). Description Body length 14.16-16.56 mm; clypeus subtriangular, mandible 4 dentate with two cutting edges on 3 rd and 4 th interspace, supra clypeal area medially flattened and sloping at the sides, scutellum finely punctuate and rounded , slightly overhanging on metanotum; wings fusco-hyaline, abdomen above with rich fulvous red, T6 disc covered with suberect dark greyish pubescence, Intermediate and posterior tarsi fulvous red on the underside, Scopa white from S2 to S6, S6 sparsely covered with black hairs.

Material examined
In Pakistan majority of the researchers focused their studies on the role of bees in crop pollination rather than taxonomic or faunistic approaches such as Ahmad (1976) reported non-Apis bee's species while studying alfalfa pollinators. Fiaz (1977) studied non-apis bees on citrus. Ascher and Rasmussen (2010) reported 250 bee species from Pakistan, out of which 45 species belong to family Megachilidae, without describing their distribution detail. Rehman et al. (1990) studied bees fauna concerned with mango pollination whereas Jasra and Rafi (2003) studied pollinator fauna of apricot from Gilgit-Baltistan.
From India, Gupta (2003) reported 25 genera of family Megachilidae with 225 species; whereas Ghorpade (2009) reported 53 genera, however some of the genera have been synonymized. Wu (2005) recorded fourteen new species of Megachile Latreille belonging to 7 subgenera which were collected from Yunnan, China. Wu (2006) recorded and redescribed five species from China, with a key to them in her Fauna sinica.
The knowledge on the Megachilid fauna of Pakistan is insufficient and poorly explored, due to lack of field surveys O n l i n e

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Taxonomic Studies of the Genus Megachile 7 and taxonomic works, which highlights the need for proper exploration of this region and further conservation of this important pollinator group. Summarizing knowledge of Pakistani Megachile is the first step towards more thorough description and characterization of the regional fauna.

CONCULSIONS
Exploring wild bee fauna is a vital step for assessing their role as crop pollinators. This will ensure the achievability of pollination services in future. In order to accomplish these targets comprehensive studies on wild and native bees particularly in Megachilidae in Pakistan are still lacking. Despite their diversity and economic importance, leafcutter bees are taxonomically poorly studied in Pakistan. Therefore, a gap in the knowledge of Megachilid bee in the country needs to be filled. Thus, this study will highly improve our knowledge of Megachilinae fauna.

ACKNOWLEDGEMENT
Authors are grateful to Dr. Joseph Monks, Natural History Museum, London for help in species identification and providing literature. We would like to thank two anonymous reviewers for their helpful comments on an early version of this manuscript.

Funding
This work was supported by Pakistan Forest Institute (PFI), Peshawar under the ADP project "Strengthening of Forestry Education at PFI, Peshawar".

Statement of conflict of interest
The authors have declared no conflict of interest.