Philippines 2014

The first trip in the context of my project on Southeast Asian pholcids brought me to the Philippines. Collecting concentrated on Mindanao, but I also had the opportunity to visit some smaller islands in the Visayas (Negros, Bohol, Camiguin, Dinagat) as well as Luzon.

The Philippines are well known for their extraordinary biodiversity, but very few pholcid spiders had been described from the country. The early and promising start was made by Eugène Simon, who visited Luzon in 1889 and three years later described four species, two of them representing new genera (Calapnita and Uthina). After that, not a single new pholcid species was described from the Philippines for more than 100 years. Christa Deeleman added a couple of species in the 1980ies (one of them the type species of the genus Panjange), and I added another six species between 2003 and 2011 (including the type species of the genus Aetana).

Our trip reavealed very clearly that these twelve species were nothing compared to the immense diversity to be discovered and described. Our data suggest that the islands are home to many dozen, more probably hundreds, of species, especially in the genera Aetana, Belisana, Panjange, and Pholcus.

Twin Lakes National Park in Negros Oriental: a beautiful pair of crater lakes surrounded by well preserved forest 

One major aim was to collect representatives of some genera that had not been available for DNA sequencing, notably Panjange, Aetana, Calapnita, and Holocneminus. We quickly reached this goal. Most exciting however, was the discovery of several species (in the genus Panjange) with strongly asymmetric male pedipalps. Genital asymmetry is common in insects but exceedingly rare in spiders (cf. Huber et al. 2007; Huber 2010). The new cases in Panjange heve since been published (Huber & Nuñeza 2015).

Other highlights were the discovery of a very unusual Aetana with highly aberrant male pedipalps (lacking the procursus, the most distinctive male genital structure in Pholcidae; photo below left; meanwhile published in Huber et al. 2015), and the discovery of further cases of egg parasitism (only one case had previously been known in Pholcidae; meanwhile published in Johnson et al. 2018).

Males of a probably new genus (left; from Marilog, Mindanao) and of Panjange (right; from Rajah Sikatuna, Bohol).

This trip would have been entirely impossible without the help of Olga Nuñeza from Mindanao State University, Iligan Institute of Technology. It was only through her continuous effort and admirable organizational skills that we obtained the relevant permits. I also owe thanks to Eddie and Philip, the students who accompanied us for part of the trip, and our driver Titin who would not loose his calm even in the most hopeless traffic jams. Thanks is also due the German Research Foundation for financing this expedition (DFG Project HU 980/11-1).

Female Calapnita produce very distinctive eggsacs, such as this specimen form Mt. Isarog (Luzon).